1. Technical Field of the Invention
This invention relates to a process for preparing 4-alkyl-2-morpholinones from N-alkyldiethanolamines. More particularly, this invention relates to a process for the preparation of 4-alkyl-2-morpholinones in good yield and selectivity by bringing a N-alklyldiethanolamine into contact with a zinc oxide promoted copper catalyst in the presence of hydrogen.
The 4-alkyl-2-morpholinones are useful as intermediates for the preparation of surfactants as shown, for example, in U.S. Pat. No. 4,228,096 and are also useful as solvents.
2. Prior Art
Cenker U.S. Pat. No. 3,324,123 discloses a method for preparing substituted morpholones by contacting a substituted diethanolamine with a reduced copper hydrogenation/dehydrogenation catalyst such as a copper chromite catalyst containing 40 to 85 wt. % of CuO and about 60 to 15 wt. % of Cr.sub.2 O.sub.3.
Laurent and Bearn in an article entitled "The Reactions of Glyoxal with Amino-Alcohols" (Bull. Soc. Chim. Fr. 83 (1978 II), pp. 83-88) disclose the reaction of glyoxal with N-alkylaminoethanols. They report that they obtained about a 40% yield of N,N'-disubstituted-3,3'-dioxazolidines instead of the expected 2-formyl oxazolidine because of the concommitment formation of N-alkyl-2-morpholones, N-alkyl, N-(2-hydroxyethyl)acetic acids and N-alkyl-2,3-epoxy morpholines.
Schultz et al. U.S. Pat. No. 3,073,822 is directed to a process for the preparation of 4-substituted-2-morpholones by the hydrogenation of N-substituted-dialkanolamines in vapor phase in the presence of a catalyst.
Haas U.S. Pat. No. 4,695,630 is directed to a process for the preparation of polycyclic acetals by the reaction of 2,3-dihydroxydioxane with a 1,2-amino alcohol in an inert solvent.
Jankowski and Berse in a paper entitled "Preparation of Novel Derivatives of Morpholone-2" (Canadian Journal of Chemistry, Vol. 46, 1968, pp. 1939-1942) disclose a process wherein an amine acid is reacted with an epoxide to give a morpholone-2 compound.
Vieles and Galsomias in a paper published in the Bulletin of the Chemical Society of France (Bull. Soc. Chim. Fr., 1970, pp. 2529-2534) disclose a process wherein amino alcohols are reacted with halogen esters.
In an article entitled "High-Yield Syntheses of N-(2-Hydroxyethyl)-N-alkylglycine Derivatives by Reaction of Ethanolamines with Glyoxal", Synthesis, 927-929 (1987), Farfan et al. disclose the reactionof N-alkylethanolamines with glyoxal to provide high yields of N-(2-hydroxyethyl)-N-alkylglycine derivatives by conducting the reaction at an elevated temperature of about 70.degree. C.
In copending Su application Ser. No. 07/596,642, filed Oct. 12, 1990, now U.S. Pat. No. 5,066,804 and entitled "Preparation of Alkyl Morpholinones" a process is disclosed for the preparation of 4-alkyl-2-morpholinones in good yield and selectivity by reacting a N-alklylmonoethanolamine with glyoxal.